Laminated wood beams and structures are commercially available today. Commonly such laminated wood structures include a plurality of standard timbers, such as two by four's, two by six's, two by eight's, two by ten's, etc., face laminated together to form laminated members which can be used as beams, girders, columns and other heavy timber structures.
It is common practice to vary the quality or grade of lumber within the laminated structure to locate higher strength wood in areas of higher stress. It is also common practice to camber laminated timber members to off-set dead load deflection. Pressure treatment of individual laminations prior to gluing is commonly practiced to provide resistance to decay.
Veneer laminated dimension lumber substitutes are also commercially available today. Commonly such laminated wood structures include a plurality of veneer type laminations of about one-eighth inch in thickness, all face glued. It is common practice to utilize the same quality or grade of timber throughout the entire laminated structure, irrespective of the location or placement of stress or load.
But from an application and economy perspective, conventional veneer laminated timber structures commercially available today have drawbacks. In this regard, it is common practice to utilize the same quality or grade of timber throughout the entire laminated structure, irrespective of the location or placement of stress and load. The net result of this is that the laminated timber structure is often over designed in certain areas of the structure because the same includes high grade timbers in areas where such is not needed. This results in the laminated timber structure being more expensive than called for, and consequently, often makes such cost prohibitive.